SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e1665e2cd04533256f58633127788a1c99d309ef09a92d94969d87c732e07731' 
  AND token = 'Aal7Ei2+9LDAffVo37qIlCc1KCctZcNmNormYyzhXdM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}